Fuel's Winter Project: Build It Before It Blows

[jodadejss06gt]

Yea its nice to have the cutout when you are on "kill" but i've played around on low boost levels and wot shifted I still get enough of a fire ball/boom to blow open/ bend my cut out. I was able to bend it back but then there was a leak sound and finally I just got a new one. If your car is prone to throw flames on quick shifts, better leave the cutout open.

 

[JoshK]

After a lot of research online it seems that the 8079 isn't the best turbo. A lot of guys posting that the compressor is too large for the turbine. I have a lot of room up front so I am thinking of going with a CT43-7879. Go with the 3.5" v-band .81 ar. I will probably leave the hotside that is on the car now on there unit I get the turbo and see how much work it will be to change it to fit the new turbo. If it is going to be too much work I will change it all up. The 7879 has a larger turbine than compressor, which seems to be the way to go. Talking with others, the turbos they were advising me towards had an even bigger split between the compressor/turbine. I don't want to go with a 7675 and wish I had went bigger later on. Also, when I sent my 6765 to Lethe for him to try he took a pic of mine next to his comp 6765 and the turbine on mine definetly looked larger.

 

[JoshK]

Both 6765s, mine on the left, Lethe's comp on the right.

 

[gray1622]

Sounds like you are making the right choice man. I go the biggest you can go with your down pipe too. I was suggesting the 7675 because i thought it was as big as you could go. I really wish someone would make a kit that you could run a T5 turbo with the exhaust out the back.

 

[gray1622]

Isnt that because one has a larger ar and a bigger cover?

 

[jodadejss06gt]

I was just saying 7675 because it seems like it may require the least amount of work and I'd hate for you to spend soooo much money to make all these changes and only hit a low 11 ;-) Just messing boy....can't wait to see whats in store. Love watching this thread.

 

[JoshK]

I see what you did there Jason hahaha. The 7879 is going to be the same frame size. I did think about going t6 for a little while but don't really wanna mess with that.

The compressor trim was the only difference in the two turbos above other than manufacturer.

 

[JeremyH]

Yea its nice to have the cutout when you are on "kill" but i've played around on low boost levels and wot shifted I still get enough of a fire ball/boom to blow open/ bend my cut out. I was able to bend it back but then there was a leak sound and finally I just got a new one. If your car is prone to throw flames on quick shifts, better leave the cutout open.

These are bolt flange style cutouts so either open or capped, not the valve style.

After a lot of research online it seems that the 8079 isn't the best turbo. A lot of guys posting that the compressor is too large for the turbine. I have a lot of room up front so I am thinking of going with a CT43-7879. Go with the 3.5" v-band .81 ar. I will probably leave the hotside that is on the car now on there unit I get the turbo and see how much work it will be to change it to fit the new turbo. If it is going to be too much work I will change it all up. The 7879 has a larger turbine than compressor, which seems to be the way to go. Talking with others, the turbos they were advising me towards had an even bigger split between the compressor/turbine. I don't want to go with a 7675 and wish I had went bigger later on. Also, when I sent my 6765 to Lethe for him to try he took a pic of mine next to his comp 6765 and the turbine on mine definetly looked larger.

Comp's made in house turbine casting is lighter and has less material, where as the precision turbine housing still uses the older garret designed casting and is thicker in a few areas. I have run 3 different precision turbos and 1 comp on my car. I still have my precision T4 turbine housing at the house. A T4 frame is a T4 frame inlet to outlet dimension wise, precision calls the vband discharge 3 5/8" (OD) comp calls it 3" (ID) but they are the same size and interchangeable.

Isnt that because one has a larger ar and a bigger cover?

The compressor cover size can be changed independently. But yes different ar's will also have a different measurable size from throat to nozzle on the turbine housing. A is the surface area from nozzle inlet to throat and R is the radius at the nozzle throat. So a smaller AR will have less area and a smaller radius at the throat than a larger AR so yes it will appear and measure different.

 

[JoshK]

Just got off the phone with comp. They agreed that the 80 compressor would be too much for the 79 turbine. Recommended a 7879 with a .96 ar and a 3.5" downpipe. Will have to get Jeremy to order that for me

 

[gray1622]

Cool man. Are you going keep the stock crank? I been wanting see some one push one to 1000+ rwhp.

 

[JoshK]

That's the plan right now

 

[JoshK]

If anyone has a junk x or h-pipe laying around they would be willing to cut the ball ends off of lmk.

 

[jodadejss06gt]

I'll just leave this here for you Jeremy ;-)
http://www.s197forum.com/forum/showpost.php?p=2021403&postcount=30
http://www.s197forum.com/forum/showpost.php?p=2031926&postcount=31

Pretty sure I've seen the electric motor on Al's turbo kit set up the exact same way. The only ones I've seen have been this oval shape.

I have the stock H pipe thats been un modified.

 

[JoshK]

Huh, here I thought all the jpc kits were forward facing and didn't go over the a-arms

 

[jodadejss06gt]

They really have a sweet kit and they've made more than 1k numerous times. Same exact turbo on that car as mine. 1205 through an auto. Just sayin! That motor is more efficient so you'd max the turbo on a 3v quicker.

 

[JeremyH]

I'll just leave this here for you Jeremy ;-)
http://www.s197forum.com/forum/showpost.php?p=2021403&postcount=30
http://www.s197forum.com/forum/showpost.php?p=2031926&postcount=31

Pretty sure I've seen the electric motor on Al's turbo kit set up the exact same way. The only ones I've seen have been this oval shape.

I have the stock H pipe thats been un modified.

You can definetly use an electric one, but it will eventually fail and be prone to issues from what I have seen. So why waste the money imho, those things aren't cheap.

I like the idea of a cheap ebay 60mm wastegate that you can plumb onto your downpipe and have it open at a desired boost level. It will be mechanical and more reliable.

Huh, here I thought all the jpc kits were forward facing and didn't go over the a-arms

Nope, that's the coyote kit, it's not forward facing.

Its that 3v "race" kit that has the forward facing headers.

They really have a sweet kit and they've made more than 1k numerous times. Same exact turbo on that car as mine. 1205 through an auto. Just sayin! That motor is more efficient so you'd max the turbo on a 3v quicker.

Actually its the other way around, a smaller motor moving less air and with less ve can push a higher pressure ratio with the same size turbine. But end results are usually similar based on starting power.

 

[jodadejss06gt]

I agree with you as I am the one thats had multiple problems with my old one. Everytime there was a fireball or quick shift it would bend the valve open. The bolt in one would be a pain though. I'm interested in the wastegate version though....It would be weird having it keep opening and closing though. Have you seen anyone do that?

 

[JeremyH]

I agree with you as I am the one thats had multiple problems with my old one. Everytime there was a fireball or quick shift it would bend the valve open. The bolt in one would be a pain though. I'm interested in the wastegate version though....It would be weird having it keep opening and closing though. Have you seen anyone do that?

We were going to do it on Bobby's car, two cheap wastgates on the downpipes but we went with the 3 bolt cutouts instead, he leaves them open all the time. A lot of exhaust still goes through the mufflers and side exhaust and then when he is boosting and pressure goes up it starts to favor the cutout path a lot more. Sounds awesome too.

You can remove or cap the cutout on our kits without even jacking up the car, they point towards the outside and are easily accessable, we use 3 wing nuts to hold it on and it takes about 5 min to remove them or cap them.


What do you mean by it would be weird having a gate on the downpipe open and close? This would be for guys that don't want a cutout open all the time. If you only wanted to relieve backpressure when above say 10psi, put a 10psi spring in the gate and it will only open to relieve pressure when your boosting above 10psi etc. Also a wastegate is designed for higher pressure/temperature use.

 

[jodadejss06gt]

With my Cutout open a lot still goes out the mufflers as well. I'd have to go back and look at bobbies pics, but I doubt his has to make a sharp turn to get out of the cutout either. Mine is a Y right before the Y pipe going to my over axle pipes. . I understand the concept. Not saying it wouldn't work, I'd just like to see it in action that is all. a nice big gate would most likely be more beneficial. You could just run a secondary dump tube, just like the normal wastegate. It would look nice sitting right beside my primary dump tube.

Its hard to see here but my cutout requires little direction change to flow outward with still plenty coming through the mufflers.

 

[JeremyH]

It would look good in there and yeah you could dump it just like the gate you use on the up pipe for boost control. That's the key to relieve backpressure better is to get it closer to the turbine(in that first 20-30%/2-3ft stretch of the downpipe).